I have a 3GS. I recently jailbroke it, but I have not installed any themes or even Winterboard for that matter. I hated the slowness I had on my 3G with these things. I have installed a few apps and 5dock. I changed the fonts, too. For some odd reason, when my phone rings, like while at work, I hit the volume button(up or down) to shut it up. It stops that ring...next ring plays, I hit the volume again and then I get a black screen with a bunch of letters. The phone stops ringing and then I get a message that says the springboard crashed and I needed to respring or restart. I have restarted twice and this continues. This is new. Was not an issue days ago. Note: This was not an issue until I loaded Fontswap. That's the last thing to be installed on my phone.